Slack adjuster



A ril 20 192a. 1,581,438

D. GRATTAN. v

SLACK ADJUSTER Filed Sept. 26, 1925 l IN VENTOR ATTORNEYS Patented d Apr. 20, 1926.

U-NIED '5 1,581,433 P ATE N'T OFFICE.

DAVID GRATTAN, or 'Los momen smack ADJUSTER;

Application filed September 26,1925. Serial No. &840.

To all whom it may concern-.-

Be it known that I, DAviD GRATIAN, a citizen of the United States, residingat Los Angeles, in the county of 'Los 'Angeles, State of California, have invented certain new and useful Improvements in Slack Adjusters, ot which the following is a specification.

This invention relates to an improvement in automatic slack adjusters for use with the air brake equipment employed on railway cars. 1

or mechanism liable to get out of order orto require periodic and thorough lubrication to insure proper operation. I v 1 A further advantage resldes 1n the fact that the higher braking e'fiiciency obtained by the present invention as organized in the braking equipment will enable the .engineer to stop the train in an emergency much more quickly and will always make it possible to bring about'a smooth and easy stop, the shocks and "jerks being eliminated, whereby the liability of accidentsto persons on the train is greatly reduced.

' Other objects and advantages residein certain novel featuresof the con truction, arrangement and combination of parts which will be hereinafter more fu'lly described and particularly pointed" out in the appended claims, reference bein hadto the aeeom, I

' sleeve 14. The bar 181mg a: flattened porpanying drawings forming a part of specification, and which? Figure l-is a view in ele'vationshowing the manner inwhi-ch the dev" is applied, Figure 2 'isa view in central longitudinal vertical section taken on the line of- Fi ure 1 parts beingS htiW-fi iile lvtrtifin fr the sake of illustration,

Figure is a vie "'n eressaseeudn onthe a lines- 3 er Figui Figuret is a sinner new The object of the present invention is to side Figure 5 is a viewin-end elevaition looking toward the right of Fig. 2, and

Figure 6 is a fragmentary detail view in perspective showing the camming element for one of the pawls.

Referring to the drawings the numeral 1 designates 'generally the slack adjuster constituti-ng the presentinvention, and this comprises a cyl-i-Indricalcasi-ng 2 having brackets 3 spanning-a truck bolster 4 and secured thereto by. bolts and nuts 52 9 At one end the casing 2' has a tapering integral head 6 merging into an integral tubular guide 7. The tubular guide 7 is "preferably of cylindrical iorm. and provides an elongated cylindrical guide opening 8. V A head plate l'0'is secured by bolts (and nuts 11 ton flange 12 formed on the end of the cylindrical casing 2 opposite" the head (3 and guide '7. Centrally the hea'd 'plate has a guide opening 13 in whicha sleeve 14 is slidably fitted. The outer end of the sleeveprojects beyond the guide and the .c inner endof the sleeve carries a circular plate 15 "which has its periphery slidably engaging the inner periphery of the inner casing 2. VA coil spring 16 is placedion the sleeve ll'within the cylindrical casingfl and has one end abutting the head plate 10 and the other end abutting the circular plate of the sleeve =14. The spring- 16 is ten sion'edto'force the sleeve into the cylind rical casing 2. v The outer end of the sleeve 14 is I closed by an integralend wall on which an apertured'lug 14 is integrally formed. To the lug 140-116 end of a chain 17is-positively connected and the-other end of the chain is connected with the live lever-Lot the con- "ventional braking equipment or if'pre'ferred to the top brake rod which connects with the live lever.

An:adjusting"bar- 1 8 is slidably fitted in the guide 7 and in the guide opening of the tion which isformed with a plurality of notches '19. A pawlQO is} pivoted, as at 21, to lugs; 22 integral-Informedwith or suitably secured-to the plate-15am thispawl 20 (:0- acts with the notches-1:901 tile-her 1 8.

The pawl 20 the lugs: 220111 which-th operable with inclined cam shoulders 25 provided on the walls of the slot An anchoring pawl 26 is pivotally mounted, as at 27, on the casing 2 and also co-acts with the notches 19 of the bar 18, the pawl 26 operating through a slot 18 in. the casing 2. A finger piece 28 is provided on the pawl 26 and affords a means whereby this pawl may be released and blocked when it is necessary to pull the adjusting bar 8 out as for instance when new brake shoes are being applied.

A hinged cover plate 30 is provided for the slot of the casing and the pawls and is releasably secured in position by any suitable locking or fastening means.

The portion of the casing 2 which lies be tween the slots 23 and 18 provides an abutment 31 wlth which the pawl 1s engageable in certain phases of the operation that -W1ll.

hereinafter more clearly ap sear.

The dead lever D of the conventional braking mechanism is pivotally connected, as at 32, to a laterally extending arm 33 rigidly connected to one end of the adjusting bar 18.

lVhenthe brakes are applied on the train and the piston in the braking equipment of any car travels farther than it should, the chain 17 connected to the live lever will be pulled thereby and will in turn draw the sleeve 14: outwardly against the tension of the spring 16. This outward movement of the sleeve it further compresses the spring 16 due to the fact that the plate-l which is rigidly connected to the sleeve and against which one end of the spring abuts moves toward the head against which the other As the sleeve let with which it is engaged when it is moved to the left, as viewed in Figure 2. If the pawl 20 moves a greater distance than that which separates two adjacent notches on the bar 18, its lugs 2st will ride up the shoulders and along the top of the casing 2, the lugs 24 spanning the slot 28. During this action the bar 18 is held against movement to the left,

as viewed in Fig. 2, by the anchoring pawl 26. lVhen the brakes are released the sprlng 16 expands and forces the sleeve 14 inwardly.

'This also carries the pawl inwardly. The,

pawl 20 engages the bar 18 one notch to the left of the point where it has previously engaged the bar and thls results in a shifting v of the bar 18 to the right as viewed in Fig. 2

a distance equal to the spacing of the notches. In this way the excess of piston travel is taken up step by step. The anchoring pawl 26 does not interfere with the movement of the bar 18 to the right as viewed in Fig. 2. .VVhen the sleeve 1 1 and the pawl20 carried thereby are moved to the right or inwardly of the casing fzas tar as they may the pawl 20 is engaged with the abutment 31 and thereby is held in engagement with its notch in which it is seated. The shifting of the bar 18 to the right shifts the fulcrum 32 of the dead lever D and thus compensates for the excessive piston travel. In order to facilitate the replacing of brake shoes a number of small sockets or holes eO may be provided in the sleeve and a small lug 41 may be provided on the head of the casing. A bar or lever may be tulcrumed on the lug 41 and have one end engaged with one of the sockets and used to draw the sleeve outwardly so as to compress the spring 16 to such an extent as to facilitate disengagement of the pawls from the notches in which they are seated.

The outer end of the guide 7 is obstructed by a bolt 85. Of course, this guide is slotted to permitthe arm 33 to extend therefrom and connect up with the dead lever.

I claim:

1. An automatic slack adjuster for use with conventional railway brakes having the usual live lever and dead lever and comprising a casing having an elongated guide at one end, an adjusting bar slidably fitted in the guide and having a plurality of notches, a sleeve slidably fitted on the bar, spring means between the casing and the sleeve urging the sleeve inwardly of the easing, a pawl connected to the sleeve and engageable with the notches of the bar, an abutment on the casing engageable with the pawl for holding it in one of the notches or" the bar when the pawl and abutment are en 7 gaged, an anchoring pawl pivoted on the casing and engageable with the notches of the bar, and a chain between the sleeve and the live lever.

2. An automatic 'slack adjuster for use with the conventional brake equipment hav ing the usual live lever and dead lever and comprising a stationary casing fixed on a truck bolster and having an elongated guide at one end and a head provided with a guide opening at its other end, an adjusting bar slidably fitted in the elongated guide and connectcd to the dead lever, a bar having a plura'lity of notches, a sleeve slidably fitted on the adjusting bar in the guide opening and having a plate at its. inner end, a spring between the head and the plate, a pawl pivoted on the plate and engageable with the-notches of the bar, an anchoring pawl pivoted on the casing and also engageable with the notches on the casing engageable with'the pawl for holding it in one of the notches of the bar.

when the pawl and said means are engaged, and a connection between the sleeve and the live lever. c v

4:. An automatic slack adjuster for use with conventional railway brakes having the usual live lever and dead lever vand coinpris- 7 ing a casing having guide means, an adjusting bar shdably fitted 1n the guide means and having a plurality of notches, a sleeve slidably' fitted on the bar, spring means between the casing and sleeve for urging the sleeve inwardly of the casingya pawl connected to the sleeve and engageable with the I notches of the bar, cO-operable means hetween the pawl and the casing for constraining the pawl toexert a step by step movement in the bar, an abutment on thecasing engageable with the pawl for holding it in one of the notches of the bar when the pawl and abutment are engaged, and a connection between the sleeve andthe live lever.

5. An I automatic slack adjuster for use with conventional railway brakes having the usual live lever and dead lever and comprising a casing having a guide, an adjusting bar slidably fitted in the guide and having a plurality of notches, a sleeve slidably fitted on the bar, spring means between the casing and the sleeve for urging the sleeve inwardly, a pawl connected to the sleeve and engageable with'the notches of the bar, said casing having a slot accommodating the pawl in certain of its movements, said casing and said pawl having oo-operating camming means for lifting the pawl from the, notches of the bar when it has moved a predetermined distance with respect tothe bar, means on the casing engageable with the pawl for holding it on one of the notches of the bar when the'pawl and abutment are engaged,-

and a connection between the sleeve and the live lever.

I 6. An automatic slack with conventional railway brakes havingthe usual live lever and dead lever and comprising a casing having a guide, an adjusting bar slidably fittted in the guide and having a plurality of notches, a sleeve slid-ably adjuster for use fitted on the bar, spring means between the casing and the sleeve for urgingthe sleeve inwardlyQa pawl connected to the sleeve and engageable with the notches of the bar, said casing having a slot accommodating the pawl in certain of its movements, said casing and said pawl having co-operating cannning means for lifting the pawl from the notches of the bar when it has moved a predetermined distance with respect to the bar,

means on the casing engageable' with the pawl for holding it on one of the notches of the bar when the pawl and abutment are engaged, and aconnection between the sleeve and the livelever, said casing having a cover for the pawls.

. v DAVID GRATTAN. 

